“最大约数问题”

正整数x 的约数是能整除x 的正整数。正整数x的约数个数记为div(x)。例如,1,2, 5,10 都是正整数10的约数,且div(10)=4。-" The most about several questions"　about the number of the positive integer x is a positive integer divisible by x. The approximate number of positive integer x is denoted by div (x). For example, 1,2, 5,10 are positive integers 10 approximately, and div (10) = 4.